# Service bulletin TSB210020\-011320

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 10212542
- Published by NHTSA: 2022\-05\-31
- Manufacturer's number: TSB210020\-011320
- Manufacturer's date: 2022\-01\-13
- NHTSA component: POWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE \(ECU/ECM\); ELECTRICAL SYSTEM

## NHTSA's summary

This Technical Service Bulletin describes the verification and resolution of an issue with Allison Transmission® Fault P2637 being caused by the Engine Control Module \(ECM\) Calibration. Cummins is releasing ECM calibration revisions that reduce occurrences of Allison Transmission® fault P2637.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2022/MC-10212542-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2022/MC-10212542-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Electrical system, Engine, Transmission and driveline, Automatic transmission, Engine control module

## Trouble codes named

P2637

## Vehicles listed

- CUMMINS B6.7
- CUMMINS L9
- CUMMINS X15

JSON: [/v1/bulletins/10212542](/v1/bulletins/10212542)

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